I am currently trying to get two of these things running Illumian. I don't have
any particular performance requirements, so I'm thinking of using some sort of
supported hypervisor, (either RHEL and KVM or VMware ESXi) to get around the
driver support issues, and passing the disks through to an Illumian guest.

The H310 does indeed support pass-through (the non-raid mode), but one thing to
keep in mind is that I was only able to configure a single boot disk. I
configured the rear two drives into a hardware raid 1 and set the virtual disk
as the boot disk so that I can still boot the system if an OS disk fails.
Once Illumos is better supported on the R720 and the PERC H310, I plan to get
rid of the hypervisor silliness and run Illumos on bare metal.

Thank you for the feedback Greg.
Using a hypervisor layer is our fall-back position. My next attempt
would be SmartOs if I can't get the cards swapped (the R720 currently
has a Broadcom 5720 NIC).

To follow up, the H310 appears to be useless in non-raid mode.

The drives do show up in Solaris 11 format, but they show up as unknown,
unformatted drives. One oddity is the box has two SATA SSDs which also
show up the card's BIOS, but present OK to Solaris.

I'd like to re-FLASH the cards, but I don't think Dell would be too
happy with me doing that on an evaluation system...